Cytological Diagnosis of Giant Cell Lesions in Infants-A Red Herring

Abstract

Introduction: Head and neck swellings and nodules are commonly seen in the pediatric population with most of the lesions falling in the benign neoplasm category. Auricular tumors are relatively rare with most common swellings being infective or congenital. Giant cell mesenchymal tumors are an entire spectrum of tumors and they are rarely been reported on the pinna. Pilomatricoma is an unusual, relatively rare, slowly growing benign tumor of the skin appendages. The histomorphological features of pilomatricoma are characteristic, but the cytological diagnosis remains problematic because of mimickers with other small round blue cell tumors. Here we present a case of pilomatricoma which presented with diagnostic pitfall in cytological diagnosis Case: A two-and-a-half-month-old female child presented with a slowly growing fleshy pinkish whitish firm swelling at the medial aspect of the right pinna for last 1 month. The swelling was painless and was not associated with other symptoms like fever, discharge from the lesion or external ear, any hearing loss or ulceration and destruction of the surrounding area. FNAC was done and scant blood mixed material aspirated. Smears showed presence of few clusters of mononuclear round blue cells with few spindled cells with fair number of giant cells admixed with very scant amorphous pink material on a hemorrhagic background. A diagnosis of giant cell mesenchymal lesion was made, and histopathology was advised. Histopathological examination revealed presence of giant cells against intradermal keratin admixed with ghost cells and basaloid to mononuclear intermediate cells. A diagnosis of pilomatricoma was made. Conclusion: The case highlights how giant cells on cytology may masquerade as giant cell mesenchymal lesion in a classic case of pilomatricoma from an uncommon location like pinna in a pediatric patient and may act as a diagnostic pitfall for the cytologist.